1. Field of the Invention
The present invention relates to the field of imaging systems and specifically to an imaging system for medical and other applications in which the internal structures of an overall object can be seen without invading or damaging the object.
2. Description of Related Art
X-Rays using film and other detectors have had medical and industrial application for over one hundred years. Ultrasound has been used for certain medical and industrial applications for about 50 years. Computer-Aided Tomography (CAT) scanning (utilizing both ionizing radiation and radioactive tracers) and Magnetic Resonance Imaging (MRI) technology have been used for about 30 years. All of the ionizing radiation systems have dangers and risks associated with their use, particularly to human subjects. The MRIs are less invasive but use a large and very expensive superconducting magnet, which makes them stationary and quite expensive to use.
The present invention is an attempt to reduce the costs and risks associated with (for example) medical imaging of internal structures and organs of the human body; and to produce a portable, safe, noninvasive and inexpensive instrument for clinical and field use. Such an instrument has broad use in industry (both medical and nonmedical), in security, and in veterinary and battlefield medicine. The invention came about from some particular experiences I have had in plasma physics and qualification of instruments as ground support equipment in aerospace industry. In some basic plasma research many years ago, I found that certain radio frequency waves much lower than the plasma frequency can be “anomalously” propagated deep into a plasma, and used to affect certain structures and other types of waves in the volume of the plasma. This led me to believe that certain bands of Radio-Frequency (RF) radiation could be propagated through unexpectedly large thicknesses of the human body, and perhaps used to image its tissues, structures, and organs. Some experiences in tracing “leaks” of low frequency RF energy from shield rooms and enclosures further convinced me that sub wavelength localization of RF waves is possible. I also learned of scanning optical microscopy (for example, confocal microscopy), in which a mechanically-scanned tiny aperture is used to create an image with extremely fine resolution, even better than that indicated by the Rayleigh criterion. Also, by using relatively large wavelength electromagnetic wave transmission and scattering by structures, the body can be used to create a finely detailed image of its internal structures.
The present invention uses both of these effects (anomalous propagation—and ordinary propagation for certain frequencies—and evanescent propagation—and sub-wavelength sub-Rayleigh criterion resolution by use of scanned apertures) to create images of the internals of the human body, or of other subjects such as animals, solid rocket grains, and so on (any non-electrically conductive subject of X-Ray, CAT, or MRI technology, any non conductive subject of ultrasound imaging, and classes of subjects yet to be determined).
Accordingly, what is needed in the art is a new type of imaging system for medical and other applications in which the internal structures of an overall object, such as the human body, must be seen without invading or damaging the object, by transmitting electromagnetic waves of single or a multiplicity of frequencies through the object and measuring the absorption and scattering of these waves by the various structures and inhomogeneities of the object, using spatially-scanned sub-wavelength resolution detectors.
It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed.
However, in view of the prior art in at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.